1. Field of the Invention
The present invention relates to a multi-fan assembly, and more particularly to a multi-fan assembly wherein the member fans of which can vertically oscillate while revolving about the common shaft of the multi-fan assembly, both of the pitching angle and the revolution of the member fans can be adjusted and fixed instantly by method of remote control or wire control.
2. Description of the Prior Arts
To avoid confusion during the course of this presentation, here are definitions for some words used in following descriptions as below:
Rotation: the spinning of fan blades of the member fan rounds its own axis or the circular movement of a rotatable member moving round a central shaft.
Revolution: the circular movement of two or more member fans rotating about a common central main shaft.
Cooling frequency: the member fan to finish a whole circle revolution.
Conventional multi-fan assembly is normally provided with two or more member fans 91 at outside of a rotary assembly 92 (as shown in FIG. 1) so as to provide cooling air from multi-direction or by radial way. The pitching angle of the member fan 91 is adjusted and fixed by manual way via a fixing member. This kind of multi-fan assembly is able to provide good effect of blowing air, however, there are still some disadvantages of which need to be improved as follows:
First, due to the pitching angle of the member fans 91 is fixed and unchangeable during the revolution of the rotary assembly 92, the cooling effect of the multi-fan assembly of this kind is limited.
Second, since the pitching angle of the member fans 91 only can be adjusted by manual way, it is very laborsome and time-consuming.
Third, the revolution speed is unadjustable. If the revolution speed is fixed, the users sitting around a bigger table will enjoy less cooling airflow provided by the member fans 91 than the users who sit around a smaller table. That is to say, the revolution speed should be adjusted at a direct proportion to the working radius of the member fans 91, so as to provide enough airflow for the respective users. The revolution of the conventional multi-fan assembly is driven by the rotation of the member fans, it is found in practices that the bigger the working radius of the member fans is, the slower the revolution speed will be, and vice versa. However, this characteristic of the conventional multi-fan assembly just runs counter to the user's needs. In order to maintain a constant cooling frequency, the bigger table with larger working radius need to revolve at a faster speed, so that the sitting persons around the bigger table will enjoy the same frequency of cooling effect.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional multi-fan assembly.